Sunitinib (Sutent)

Experimental layout for VEGF signaling blocking and LCMV infection in WT mice. Mice received two injections on day 0 and 3 p.i. of Abs as described in Material and Methods, or daily gavage of the VEGFR/PDGFR-inhibitor sunitinib. Inguinal LN volume on day 0 (D0) or day 8 (D8) p.i. after treatment of mice with control Ig or anti-VEGFR2, anti-VEGF-A Abs or sunitinib. Pooled from 1-2 independent experiments with 3-5 mice per treatment. D. Total HEV length on day 0 (D0) or day 8 (D8) p.i. as in C. No significant difference was found in C and D between day 8 control Ig and Ab- or inhibitor-treated values.

Sunitinib limits the colonial growth of HT-29 by downregulating HIF-1a. (A) The number and size of colonies formed in soft agar. The numbers of small colonies (<50 lm diameter) were not different among conditions of a serial concentration of sunitinib. On the contrary, large colonies (>50 lm diameter) disappeared after incubation with sunitinib. Each point represents the mean and SD from four separate experiments. (B) HIF-1a expression and hypoxia within HT-29 colony. After colonies grew for 4 weeks, HIF-1a and hypoxia were visualized by immunofluoroscence staining. Bar = 20 lm.

. Sunitinib downregulates HIF-1a. (A) Dose-dependent repression of HIF-1a protein level by sunitinib in HT-29. HT-29 cells were incubated under normoxic (N) or hypoxic (H) conditions in the presence of sunitinib for 24 h. HIF-1a and ARNT proteins in total cell lysates were analyzed by Western blotting. (B) Sunitinib attenuates the hypoxic induction of HIF-1 target genes. RNAs were isolated from HT-29 cells subjected to normoxia (N) or hypoxia (H) in the presence of sunitinib for 16 h. The mRNAs of HIF-1a and its target genes were analyzed by RT-PCR and autoradiography. PGK1 indicates phosphoglycerate kinase 1; PDK1, pyruvate dyhydrogenase kinase 1; CAIX, carbonic anhydrase IX. (C) Sunitinib-induced HIF-1 inhibition. Epo-enhancer and b- galactosidase reporter plasmids were co-transfected into HEK293 cells. After 16 h incubation, luciferase and b-galactosidase activities were measured.

Sunitinib inhibits 50-UTR-dependent translation of HIF-1a. (A) 50 cap-dependent translational activity of HIF-1a. The luciferase reporter plasmid contains the HIF-1a 50-UTR segment between the tk promoter and the luciferase gene. HT-29 cells were co-transfected with the reporter plasmid (8 lg per 100-mm dish) and the b-gal plasmid (4 lg). After 16 h incubation under normoxic or hypoxic conditions with sunitinib, cells were lysed and subjected to luciferase assay. *P < .05 versus the hypoxic control. (B) IRES-dependent translational activity of HIF-1a. The luciferase reporter plasmid contains the HIF-1a 50-UTR segment between the GFP gene and the luciferase gene. HT-29 cells were co-transfected with the reporter plasmid (8 lg) and the b-gal plasmid (4 lg). *P < .05 versus the hypoxic control. (C) Sunitinib inhibits phosphorylation of Akt. After 8 h incubation under hypoxic condition with sunitinib, HT-29 cells were lysed and subjected to Western blotting. (D) Sunitinib suppresses HIF-1a in VHL-null RCC4 cells. VHL (-/-) RCC4 cells were incubated under normoxic conditions sunitinib for 8 h, and HIF-1a in total cell lysates was analyzed by Western blotting.

Combinational treatment of kinase inhibitors induces the similar phenotype produced by PP1. All images are lateral view with dorsal to the top and anterior to the left. The combinational treatment of Dasatinib (D) or U0126 (U) with Sunitinib (SU),PTK787 (PTK), or ZM323881 (Z) resulted in the shrinkage of dorsal aorta.